Welcome to the weather blog - a regular Monday through Friday discussion of the weather! While the discussions usually will only come on days I'm working, I'll issue special updates when the weather warrants. I will always post to let you know when no discussion is expected if I'm away on vacation, etc. - if no update is here and no info is available, that likely means the server has temporarily gone on the fritz and I will update as soon as technically possible. You'll find a quick weather synopsis linked to the daily forecast at the top of the page, a general non-technical weather summary below, and when available (most days) a detailed technical meteorological discussion will follow by mid-afternoon. My email is contact@mattnoyes.net. This blog is for you, so I hope you enjoy it! -Matt Noyes
General Weather Summary:
Reminder: The podcast and written discussion are now being posted separately, for those of you who subscribe to either or both of the feeds to easily decipher between podcasts, issued relatively early in the morning, and the written discussion, which comes around late-morning most days.
It certainly looks and feels as if New England has jumped back into the depths of winter after Friday's snowstorm for many! Cold air has consumed the Northeastern United States with a "trough," or dip in the jet stream, firmly in place. As is often the case in March, much milder air waits across the Central United States, where temperatures jumped into the 80s as far north as Nebraska, and neared 80 in South Dakota, on Sunday. A piece of this warmth will run at New England by week's end, eventually bringing another big swing in weather over a short period of time.
For now, winter rules. Over a foot of new snow in a large part of New England melted to create patches of Monday morning black ice upon refreezing on entrance and exit ramps, as well as secondary roadways, but ample sunshine was already warming the ground and the atmosphere Monday morning, and will continue to have an influence throughout the day. With a large area of high pressure - fair weather - parked over the Mid-Atlantic coast and drifting slowly east, the clockwise flow of air around this fair weather cell will mean a southwest wind for most of New England through Monday, gradually filtering warmer air into all six states. The result of this teamwork between a mild wind and sunshine will be temperatures above the melting point for all but northern Maine, creating widespread melting, and resultant road spray and solar glare, which will mean drivers will either be donning their shades or squinting through the day! Clouds will increase high in the sky - cirrus clouds made of ice crystals - during the afternoon and into the evening.
The approaching clouds come in advance of a strong energetic disturbance aloft, well defined on satellite and radar imagery across the Central Great Lakes Monday morning, and moving steadily east. In response to the approach of this moisture and energy, clouds will lower and thicken Monday evening, yielding areas of light snow for many Monday night. Estimated time of arrival is 7-9 PM in Western New England and 9-11 PM in Eastern New England. Areas of light snow will be relatively short-lived, lasting only until the pre-dawn hours and dropping varying amounts across New England, but light accumulation overall. The variation in Monday night snowfall will depend heavily on temperatures in the lowest few thousand feet of the atmosphere, which will still be above freezing for much of Southern New England after a day near 40 degrees. A thin layer of above-freezing warmth is likely to linger in the valleys of Southern New England - especially for areas from Hartford to Providence to Plymouth points south. North of that line, warm air trapped in valleys will produce a very wet snow with only a coating to an inch of accumulation, though hilly terrain is likely to record 1"-2" of snow, and a widespread 1"-2" is also expected across much of Northern and Western New England with higher amounts in higher terrain of the mountains.
Though precipitation will have ended Tuesday morning, expect some slippery road surfaces where treatments were not heavy during Monday night - especially secondary roads and highways where the combination of re-frozen meltdown from Monday and snow from Monday night will make for some tricky maneuvering. With drier air moving in behind the departing disturbance, however, sunshine will contribute to a bright day, though an active northwest wind will gust to 35 mph at times, carrying not only drier air but also colder air into New England, meaning temperatures will struggle to get out of the lower and middle 30s - some 10 degrees below average!
Though cool and dry air will linger in New England on Wednesday with a relatively light wind and sunshine, a new and very potent disturbance will make its way off the Pacific and into the West Coast of the U.S. This disturbance will pull cold air southward with it, carving out a trough in the jet stream winds aloft across the Western third of the nation, and thereby forcing the bubble of warmer air over the Central United States to break east and move toward the Northeast. By Wednesday night into Thursday, I expect rising overnight temperatures as the northern periphery of this bubble of warmth pushes into New Enlgand, prompting rain showers south and snow showers north during the overnight Wednesday night. These showers will mark a battle of airmasses as cold air will be hesitant to depart, and incoming warmth eager to move in. The result will likely be lots of clouds and areas of fog lingering with a few showers leftover Thursday morning. The biggest question for Thursday is whether we could break through the clouds to bring out sunshine, and the stakes are high because with such a mild airmass in place, just a little bit of sunshine would go a long way. At this point, it appears as though the combination of dry air aloft and a west-southwest wind near the ground will favor bringing sunshine out and poking holes in the clouds Thursday, thereby allowing temperatures to warm handily with a gusty southwest wind. Fighting a warmup will be the presence of snow in many areas from this weekend's storm and only gradual meltoff, but an active wind would help to "mix" the atmosphere, largely offsetting the effects of snowpack.
Meanwhile, the disturbance that pushed into the West Coast midweek will have broken into two pieces, with one chunk of significant energy diving south across the Southwestern United States - dipping so far south it separates from the storm-steering winds of the jet stream for a time - and the northern chunk of energy racing east across the Northern Tier of the nation, steered by those fast moving jet stream winds. That northern disturbance will arrive to New England on Friday, nudging a cold front southward out of Canada and battling back against the spring warmth that will be in place Thursday and Thursday night. Showers are likely to develop along and ahead of this battlezone on Friday, especially in Northern New England early where temperatures will be held cooler due to the return of cool air, and then in Southern New England late where afternoon highs should be rather mild once again, ahead of the approaching front.
Behind the cold front, shallow cool air will settle south out of Canada for the start of next weekend, and likely stick around through Sunday. Thereafter, the last week of March looks as though it will end on a mild note, as a broad ridge of high pressure crests over the Eastern half of the nation, bringing moderating temperatures that will land above normal to finish the month.
Enjoy your Monday!
Technical Discussion: None today.
Matt
